Cleanliness distribution of high-carbon chromium bearing steel billets and growth behavior of inclusions during solidification




Billets, Distribution of inclusions, Formation sequence, Total oxygen contents


Variation of cleanliness and distribution of inclusions in thickness and width direction of high-carbon chromium bearing steel billets has been studied using total oxygen and nitrogen analysis and SEM/EDS, and the growth behavior of inclusions during solidification was studied with the help of solidification model. The region with relatively high total oxygen contents in the cross profile of billets is between inner arc side 3/16 and outer arc side 1/4; between left edge side 5/16 and right edge side 5/16. The formation sequence of inclusions is MgO-Al2O3 > TiN > MnS. MnS could wrap MgO-Al2O3 and reduces the damage to steel matrix caused by the latter, but generally could not effectively wrap TiN. Besides, TiN could wrap MgO-Al2O3 before MnS, which would weaken the protective capacity of MnS. Moreover, compared with MgO-Al2O3 inclusions, the sizes of TiN inclusions are generally larger. Thus the control of TiN inclusions should be strengthened. In thickness direction, the maximum size regions of TiN and MnS inclusions are inner arc side 1/3 and outer arc side 1/3; in width direction, the regions are edge side 1/3. During bearing processing, these regions and the regions with high total oxygen content should be avoided.


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Cornelissen, M.C.M. (1986). Mathematical-model for solidification of multicomponent alloys. Ironmak. Steelmak. 13 (4), 204–212.

Fujii, K., Nagasaka, T., Hino, M. (2000). Activities of the constituents in spinel solid solution and free energies of formation of MgO, MgO·Al2O3. ISIJ Int. 40 (11), 1059–1066.

Goto, H., Miyazawa, K., Yamada, W., Tanaka, K. (1995). Effect of cooling rate on composition of oxides precipitated during solidification of steels. ISIJ Int. 35 (6), 708–714.

Guo, J., Cheng, S.S., Cheng, Z.J. (2013). Mechanism of non-metallic inclusion formation and modification and their deformation during compact strip production (CSP) process for aluminum-killed steel. ISIJ Int. 53 (12), 2142–2151.

Hua, L. Deng, S., Han, X.H., Song Huang, S. (2013). Effect of material defects on crack initiation under rolling contact fatigue in a bearing ring. Tribol. Int. 66, 315–323.

Itoh, H., Hino, M., Ban-ya, S. (1997). Thermodynamics on the formation of spinel nonmetallic inclusion in liquid steel. Metall. Mater. Trans. B. 28 (5), 953–956.

Kubaschewski, O., Alcock, C.B., Spenscer, P.J. (1993). Thermochemical data. Materials Thermochemistry. 6th Edition, Pergamon Press, pp. 257–323.

Liu, Z.Z., Wei, J., Cai, K.K. (2002). A coupled mathematical model of microsegregation and inclusion precipitation during solidification of silicon steel. ISIJ Int. 42 (9), 958–963.

Ma, W.J., Bao, Y.P., Wang, M., Zhao, L.H. (2014). Effect of Mg and Ca treatment on behavior and particle size of inclusions in bearing steels. ISIJ Int. 54 (3), 536–542.

Mazzù, A., Solazzi, L., Lancini, M., Petrogall, C., Ghidini, A., Faccoli, M. (2015). An experimental procedure for surface damage assessment in railway wheel and rail steels. Wear 342–343, 22–32.

Moghaddam, S.M., Sadeghi, F., Paulson, K., Weinzapfel, N., Correns, M., Bakolas, V., Dinkel, M. (2015). Effect of non-metallic inclusions on butterfly wing initiation, crack formation, and spall geometry in bearing steels. Int. J. Fatigue. 80, 203–215.

Ohnaka, I. (1986). Mathematical analysis of solute redistribution during solidification with diffusion in solid phase. Trans. Iron Steel Inst. Jpn. 26 (12), 1045–1051.

Sigworth, G.K., Elliott, J.F. (1974). The thermodynamics of liquid dilute iron alloys. Met. Sci. 8 (1), 298–310.

Takada, H., Bessho, I., Ito, T. (1976). Effect of sulfur content and solidification variables on morphology and distribution of sulfide in steel ingots. Tetsu-to-Hagane 62 (10), 1319–1328.

Wang, Y.N., Yang, J., Bao, Y.P. (2014). Characteristics of BN precipitation and growth during solidification of BN free-machining steel. Metall. Mater. Trans. B. 45 (6), 2269–2278.

Wang, M., Bao, Y.P., Yang, Q., Zhao, L.H., Lin, L. (2015). Cleanliness evolution of interstitial free (IF) steel billets in the thickness direction. Chinese J. Eng. 37 (3), 307–311.

Wolf, M., Clyne, T.W., Kurz, W. (1982). Microstructure and cooling conditions of steel solidified in the continuous casting mould. Arch Eisenhüttenwes 53 (3), 91–92.

Yang, W., Duan, H.J., Zhang, L.F., Ren, Y. (2013). Nucleation, growth, and aggregation of alumina inclusions in steel. JOM 65 (9), 1173–1180.

Yang, L., Cheng, G.G., Li, S.J., Min Zhao, M., Gui-ping Feng, G.P. (2015). Generation mechanism of TiN inclusion for GCr15SiMn during electroslag remelting process. ISIJ Int. 55 (9), 1901–1905.

Yu, H.S., Li, J.G. (2015). Size distribution of inclusions in 12% Cr stainless steel with a wide range of solidification cooling rates. International Journal of Minerals. Int. J. Min. Met. Mater. 22 (11), 1157–1162.

Zhang, L.F. (2013). Nucleation, growth, transport, and entrapment of inclusions during steel casting. JOM 65 (9), 1138–1144.

Zhang, T.S., Min, Y., Liu, C.J., Jiang, M.F. (2015a). Effect of Mg addition on the evolution of inclusions in Al–Ca deoxidized melts. ISIJ Int. 55 (8), 1541–1548.

Zhang, L.F., Ren, Y., Duan, H.J., Yang, W., Sun, L.Y. (2015b). Stability diagram of Mg-Al-O system inclusions in molten steel. Metall. Mater. Trans. B. 46 (4), 1809-1825.

Zhao, D.W., Li, H.B., Bao, C.L., Yang, J. (2015). Inclusion evolution during modification of alumina inclusions by calcium in liquid steel and deformation during hot rolling process. ISIJ Int. 55 (10), 2115–2124.



How to Cite

Gu, C., Bao, Y.- ping, & Lin, L. (2017). Cleanliness distribution of high-carbon chromium bearing steel billets and growth behavior of inclusions during solidification. Revista De Metalurgia, 53(1), e089.